Correlation Analysis
Costco Wholesale Corp vs W.R. Berkley Corporation
COST vs WRB
+0.917
Very strong positive
When one moves up, the other tends to follow.
Costco Wholesale Corp
↗COST
Founded in 1983, Costco Wholesale now operates a global chain of membership-based warehouse clubs, delivering high-quality goods and services at consistently low prices. As of its most recent fiscal year, Costco operated approximately 910 warehouses, serving more than 80 million members across its three geographic segments: Costco US (approximately 73% of total revenue), Costco Canada (13%), and Costco International (14%).Costco's core value proposition—quality products at unbeatable prices—has yielded consistently strong member renewal rates (93% in the US and Canada and nearly 90% internationally). About 55% of Costco's fiscal 2025 revenue came from its grocery offerings, and another 25% from general merchandise.
Market cap 451.9B
W.R. Berkley Corporation
↗WRB
W.R. Berkley is an insurance holding company with a host of subsidiaries that primarily underwrite commercial casualty insurance. The firm specializes in niche products that include various excess and surplus lines, workers' compensation insurance, self-insurance consulting, reinsurance, and regional commercial lines for small and midsize businesses.
Market cap 24.8B · 8,804 employees
Time Series
Relative Performance
Who Moves First
COST leads WRB by 6 days
COST tends to move before WRB.
After testing 13 timing shifts, the strongest relationship was +0.919 (they moved in the same direction).
Do They Crash Together?
Correlation by Market Regime
How these series behave when markets are rising, falling, or diverging. A correlation that holds in drawdowns is very different from one that only works in rallies.
Both Rising
+0.081
14 periods · Return correlation when both series rose
Both Falling
+0.225
6 periods · Return correlation when both series fell
Diverging
-0.689
15 periods · Return correlation when series moved apart
R-Squared
84.1%
Share of variance in one series explained by the other.
Trend Agreement
59.1%
How often both series moved in the same direction period-to-period.
Overlap Quality
1,254
Deep shared window — 1,254 usable pairs.
Significance
p < 0.001
95% CI: [0.908, 0.926]
Scatter
XY Regression
Pipeline
Data quality details
Pipeline
Data quality details
Pipeline Summary
1,254 paired data points survived the daily window.
Raw input
1,254
1,254
Normalized
1,254
1,254
Prepared
1,254
1,254
Aligned
1,254
1,254
Invalid removed
0
A: 0 / B: 0
Duplicates removed
0
A: 0 / B: 0
Alignment drops
0
A: 0 / B: 0
Series A
Costco Wholesale Corp
COST
Market cap 451.9B
Stock · 1,254 raw → 1,254 prepared
Series B
W.R. Berkley Corporation
WRB
Market cap 24.8B · 8,804 employees
Stock · 1,254 raw → 1,254 prepared
Sign agreement
100.0%
How often both values share the same sign.
Zero crossings
5
Estimated crossover points between normalized spreads.
Slope
0.0555
Linear regression slope.
Intercept
13.2810
Linear regression intercept.
Related Extremes
Highest and Lowest Correlated
Saved 7 hours ago · ID: stock-cost-vs-stock-wrb-daily